Carbon Monoxide Detectors: Ultimate Guide

Carbon monoxide (CO) is one of the most hazardous gases found in the home. Known as the “silent killer,” CO gas is colorless, odorless, tasteless and non-irritating, yet it can cause unconsciousness, brain damage or death. As a result, more than 400 people die of accidental carbon monoxide exposure each year, a higher fatality rate than any other type of poisoning. 

As the weather cools off, you close up your home for the winter and count on heating appliances to keep warm. This is when the risk of carbon monoxide inhalation is highest. The good news is you can protect your family from carbon monoxide in several ways. One of the most efficient methods is to install CO detectors in your home. Use this guide to help you understand where carbon monoxide can appear from and how to make the most of your CO alarms. 

What generates carbon monoxide in a house? 

Carbon monoxide is a byproduct of incomplete combustion. As a result, this gas is generated whenever a fuel source is burned, including natural gas, propane, oil, charcoal, gasoline, woo, and more. Prevalent causes of carbon monoxide in a house include: 

• Clogged clothes dryer vent 

• Malfunctioning water heater 
• Furnace or boiler with a cracked heat exchanger
• Closed fireplace flue while a fire is lit 
• Improperly vented gas or wood stove 
• Vehicle idling in the garage 

• Portable generator, grill, power tool or lawn equipment operating in the garage 

Do smoke detectors detect carbon monoxide? 

No, smoke detectors do not detect carbon monoxide. In fact, they sound an alarm when they sense a certain concentration of smoke generated by a fire. Having dependable smoke detectors reduces the risk of dying in a house fire by nearly 55 percent. 

Smoke detectors come in two primary modes—ionization detectors and photoelectric detectors. Ionization detection works best with fast-growing fires that produce large flames, while photoelectric detection is more effective with smoldering, smoky fires. Some newer smoke detectors come with both types of alarms in a single unit to increase the chance of sensing a fire, no matter how it burns. 

Obviously, smoke detectors and CO alarms are both important home safety devices. If you look up at the ceiling and notice an alarm of some kind, you won’t always know whether it’s a smoke detector or a carbon monoxide alarm. The visual difference depends on the brand and model you have. Here are a few factors to consider: 

• Some devices are clearly labeled. If not, check for a brand and model number on the back of the detector and locate it online. You should also find a manufacture date. If the device is more than 10 years old, replace it right away. 
• Plug-in devices that draw power from an outlet are typically carbon monoxide is supposed to be labeled as such. 
• Some alarms will be two-in-one, detecting both smoke and carbon monoxide with an indicator light for each. Still, it can be hard to tell without a label on the front, so checking the manufacturing details on the back is your best bet. 

How many carbon monoxide detectors will I want in my home? 

The number of CO alarms you need depends on your home’s size, number of floors and bedroom arrangement. Follow these guidelines to guarantee thorough coverage: 

• Install carbon monoxide detectors near wherever people sleep: CO gas leaks are most common at night when furnaces must run constantly to keep your home heated. Therefore, all bedrooms should have a carbon monoxide detector installed within 15 feet of the door. If a couple of bedroom doors are less than 30 feet apart, one detector is sufficient. 
• Add detectors on all floors: 
  Dangerous carbon monoxide buildup can become trapped on a single floor of your home, so make sure you have at least one CO detector on each floor. 
• Put in detectors within 10 feet of the internal garage door: Many people unsafely leave their cars idling in the garage, leading to dangerous carbon monoxide buildup, even when the large garage door is wide open. A CO detector immediately inside the door—and in the room above the garage—alerts you of elevated carbon monoxide levels entering your home. 
• Put in detectors at the proper height: Carbon monoxide weighs about the same as air, but it’s frequently carried along with the hot air produced by combustion appliances. Putting in detectors close to the ceiling is best to catch this rising air. Models with digital readouts are best located at eye level to make them easier to read. 
• Add detectors at least 15 feet from combustion appliances: Some fuel-burning machines give off a tiny, harmless amount of carbon monoxide when they start. This dissipates quickly, but if a CO detector is positioned too close, it could give off false alarms. 

• Put in detectors away from high heat and humidity: Carbon monoxide detectors have specific tolerances for heat and humidity. To reduce false alarms, avoid installing them in bathrooms, in direct sunlight, around air vents, or close to heat-generating appliances. 

How do I test/troubleshoot a carbon monoxide alarm? 

Depending on the model, the manufacturer may recommend monthly tests and resetting to ensure proper functionality. Also, replace the batteries in battery-powered units every six months. For hardwired units, replace the backup battery every year or when the alarm starts chirping, whichever comes first. Then, replace the CO detector entirely every 10 years or according to the manufacturer’s guidelines. 

How to test your carbon monoxide alarm 

It only takes a minute to test your CO sensor. Check the instruction manual for directions specific to your unit, knowing that testing follows this general procedure: 

• Press and hold the Test button. It will sometimes take 5 to 20 seconds for the alarm to go off. 
• Loud beeping indicates the detector is operating correctly. 
• Release the Test button and wait for two quick beeps, a flash or both. If the device continues beeping when you release the button, press and hold it again for five seconds to silence it. 

Swap out the batteries if the unit fails to perform as expected for the test. If replacement batteries don’t make a difference, replace the detector immediately. 

How to reset your carbon monoxide alarm 

You only have to reset your unit when the alarm goes off, after testing the device or after changing the batteries. Some models automatically reset themselves within 10 minutes of these events, while others require a manual reset. The instruction manual will note which function applies. 

Follow these steps to reset your CO detector manually: 

• Press and hold the Reset button for 5 to 10 seconds. 
• Release the button and wait for a beep, a flash or both. 

If you don’t hear a beep or see a flash, attempt the reset again or replace the batteries. If it’s still not working, troubleshoot your carbon monoxide alarm with help from the manufacturer, or replace the detector. 

What do I do if a carbon monoxide alarm starts? 

Follow these steps to protect your home and family: 

• Do not disregard the alarm. You won’t always be able to detect unsafe levels of carbon monoxide until it’s too late, so expect the alarm is working correctly when it starts. 
• Evacuate all people and pets as soon as possible. If you can, open windows and doors on your way out to help dilute the concentration of CO gas. 
• Call 911 or your local fire department and report that the carbon monoxide alarm has triggered. 

• Do not assume it’s safe to reenter your home when the alarm stops beeping. Opening windows and doors may help air it out, but the source could still be producing carbon monoxide. 
• When emergency responders come, they will enter your home, measure carbon monoxide levels, check for the source of the CO leak and figure out if it’s safe to go back inside. Depending on the cause, you may need to request repair services to prevent the problem from reappearing. 

Seek Support from Knochelmann Service Experts 

With the right precautions, there’s no need to fear carbon monoxide exposure in your home. In addition to installing CO alarms, it’s worthwhile to maintain your fuel-burning appliances, especially as winter starts. 

The team at Knochelmann Service Experts is qualified to inspect, clean, diagnose and repair problems with furnaces, boilers, water heaters and other combustion appliances. We know what signs suggest a potential carbon monoxide leak— such as excessive soot, rusted flue pipes and a yellow, flickering burner flame—along with the necessary repairs to resolve them. 

Do you still have questions or concerns about CO exposure? Is it time to schedule annual heating services? Contact Knochelmann Service Experts for more information.